Clackamas County firefighters arrived at the location and said the victim smelled strongly of gasoline.

The man was transported to Emanuel Hospital in critical condition.

Deputies said the suspect and the victim did not know each other.

The suspect is described as a white man in his mid to late 20s, between 5 feet 10 inches and 6 feet tall. He has a medium to muscular build and was wearing a black flat brim hat with a black hooded jacket, gray sweatpants with a black stripe and black shoes.

Deputies, employees, customers and nearby business owners told FOX 12 they are stunned by the brazen and horrifying crime.

“It makes you wonder what’s going through the suspect’s head,” customer Jesse Loyer said Thursday morning. “What makes a person do that, to a stranger?”

Robert Gilliland is the manager at the nearby Stereo King. He said he now plans on checking his surveillance feeds to see if it will help deputies.

“It’s amazing what people do in this world these days,” Gilliland said. “It’s beyond me. I can’t wrap my head around it”

The sheriff's office is also investigating a possible connection to a similar case Monday night that involved gasoline being poured on a person at a movie theater across the street from the Denny's location at the Clackamas Town Center. No one was hurt during that incident, but deputies are re-interviewing the victim in that case and believe the crimes could be connected.

Anyone with information about this investigation is asked to contact the Clackamas County Sheriff’s Office. Anyone who sees the suspect is urged to not approach him and call 911 right away.

Denny's released a statement Thursday morning about the incident.

We are deeply disturbed by the senseless, random act of violence that took place at our franchised-owned Happy Valley restaurant, and our thoughts and prayers are with our guest that was seriously injured. Both guests and team members acted quickly to help this guest and ensure the safety of others in the restaurant. We are actively assisting authorities in their investigation and we ask that anyone with information to please contact the Clackamas County Sheriff's office at 503-723-4949.

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